Study: ants 'switch careers' as they get older

Ants change jobs as they age, a study that followed the lives of
individual ants has found.

The career progression was discovered by a team at the
University of Lausanene in Switzerland who tagged and tracked every
individual in six colonies of carpenter ants.

Young ants were more likely to be nurses, taking care of the
queen ant and her young, while older ants were more likely to be
foragers, gathering food for the colony. In the middle of their
"careers" the ants were commonly cleaners.

Individual ants were tagged with an unique symbol, similar to a
barcode, on their back. An overhead camera was then able to track
the movements of each of the 100 ants in each colony's enclosure.
The study, published on 18 April in the journal Science, lasted 41 days and the camera recorded the ants'
movements twice every second, resulting in billions of data points
and over 9 million interactions between the ants.

A strict social divide was found to govern the ants' lives, with
nurses and foragers rarely mixing. Cleaner ants were the only ones
to roam around the entire colony and mingle with other
groups. Around 10% of the ants were cleaners, while 40% were
nurses and 30% foragers.

"The ants can probably be in any place within their enclosures
in less than a minute," said ecologist and study lead author
Danielle Mersch in a Nature article, "but even in these simple spaces,
they organize into these spatial groups."